Sorry I did not elaborate, I was in a hurry. VV N310 is a very fast powder which means it's pressure spikes very quickly. This can be dangerous in a small case like 9mm. Competitors looking for an edge use with a heavy bullet for powder puff recoil. I used it in a .38 super and suffered one blown case head. I no longer reload for the lowest recoil possible, instead I reload for reliability and accuracy. VV N320 is safe for use in 9mm and is the fastest powder I use for that caliber. I'm using N340 in .38 super now and I really like it.